<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <style>
      .a + .b { color: green; }
    </style>
  </head>
  <body>
    <span><span class="a"></span>
          <span class="b">This should be green</span></span>
  </body>
</html>
